Lock joint



Patented Dec. 9, 1930 LUTHER n. LovEKIN,` or WYNNEWooD, PENNSYLVANIA i Application filed September 4, 19261. Serial No. 163,550.

`The general obj ect of the present invention is toV provide an improved lock joint primarilydevisedand well adapted for use under the severe conditions to which the shaft .couplings and tool and shaft connections employed inca-ble oil well drilling operations are subjected, but my improved lock joint is not restricted to such use. A more specicV object of the invention is to provide a lock one of the parts coupled by the joint is threaded into a socket formed in the other partwith a pin portion inherently stronger than has heretofore been employed. Another specific joint of the type in which a pin portion of object of the present invention is to provide a lock joint of the type mentionedY with'improved means `for locking the coupled .parts against relative rotation loosening or un# threading the joint; and the invention is 2@ characterized in particular by thecomparativeease with which al joint of the threaded pin and socket typemay lbe nia-de tightand opened, when necessary, and by the-fact that much less force is required .to sci'ew the parts together and apart than is required with the simple threaded pin and socket connections heretofore commonly employed in shaft coupling for cable oil well drilling. The relatively small force required to couple and separate parts coupled by my improved lock joint makes it unnecessary to use the powerful jack mechanism commonly employed to screw oil well drilling shaft sections together and subjecting the parts coupled to such currence for the threads to be stripped or the coupling. i y

The vario us features of novelty which charpin to be broken inthe operation of making a,

pa-rticularity in the claims annexed to and forming a part of this specification.k For a` better understanding of the inyention, how-` ever, its specific Vadvantages and objects at-V tained with itsuse, reference `-should be had to the accompanying drawings `and ,descripstresses that it has been a not infrequent ocacterize my invention arepointed out with` Fig.- 1 is an elevationpartly in section; 4 Fig. 2 is a section on the broken line 2-2 of Fig'.k l; i

Fig. 3 is a section on the line 3*,-3 of Fig. l;

Vli`ig". 4 is a section on the linea-'t of Fig. 1; 55

Fig. 'is a 4view taken similarly to Figlilf lustrating a'modiedconstruction; and j Fig. 6 isa view taken similarly to Fig. l,

illustrating'a modication.

sections coupled together by a joint constructed in accordance with the present invention. For cable oil' well drillingthe sections A and Binay -behsteel shaftseotionsSO` feet or so sections together.; VvThe shaftB is provided with a'threaded pin or tenon portion to be screwed'tothe tapered internallythreaded 70` i) outer portion Agof an aXia-l socketformed in l the shaft A; The'lpinrportionb may bezin'- .p tegral with 'the shaft Vsection B in some cases' as shown in Fig. 6, but preferably isa separate piece screwed into an internally threaded socket `-B of thesection B, `and secured to the shaft section B in` any suitable manner. As shown the pin is positively secured to the shaftsectionB by a threaded pin l screwed vinto'registering threaded openings 30 formed in the shell of the socket B and in the pin vparti).

4An untapered internally threaded inter-'i f y mediate portion A3 of the socket in the shaft member` A re'ceivesan externally-threaded 85 'i bushing or nut C which has an end portion projectinginto the unthreaded socketportion A2 betweenthe portions -Af and Af". The

socket. portions A and A3 .areoppositely threaded, thatfis to say,1if the screw thread Vin Vthesocket. A -is'aright hand thread, the

threadin-the socket A? is a left hand thread. y An axially disposed` bolt D has its head D received in the portion Atof the socket in the -member A between the end wall ofthe socket tive 'matter in whichY l have illustrated and described vention.

Of the drawings:

preferred embodiments of my inand thebushing C against which the head of the bolt bears. The body of the bolt passes vthrough the bushing C and-through an axialV passage b2 formed for the purposein the pin-v ioo I In the drawings, A and B represent shaft ,60

and 5 or 6 inches in diameter, though, of 65915 course, the invention isnot restricted to such ldimensions or, indeed, to use in coupling shaft Gil threaded outer end of the passage B4 rece1v-.

' socketportion A3.

b, into an extension B2 of the last mentioned passagejformed in the body of the shaft B.

A metal to metal contact subjected to a compression stress is maintained between the 5 adjacent ends of the pin b and bushingC in the assembled joint. Instead of having the end of the pin in directyengagement with the end of the bushing C, Ipreferably interpose a metal washer or ring E advantageously made of metal such as copper ductile enough vto be subject to some deformation under the relatively moderate force to which it is subjected by therparts Z) and C whenthe joint Vis tight. In the assembled jointthe body of the bolt D is rigidly secured to the shaft member B and put under tension by wedgingV means shown as comprising a pin F having a tapered body portion received 1n a correspondingly tapered, but slightly largerdiametral passage D2 formed the body of the bolt D, andhaving cylindrical end portions receiv'edin aligned openings B3 and B4 formed o in the wall ofthe. socket B. As shown, the

pin F is prevented. from working loose by means of aisrew plug G screwed intoY the ing the largerV end'V of the pin F. G represents a plug'normally closing anV opening in theshell of the socket portion A2 throughV which heavy grease* or V other` lubricantl may.A 'i be injected into the interior.: ofthe joint struc. ture if and when this is desirable.

i Y y Advantageouslyf as shown, the -bolt head D Ais formed with a tapered projection Daentering the tapered Nrecess at the inner end of theV socket in the member A, so that the head.

of Athe bolt D isaccurately, centered, and its rotation is facilitated. The bushing C has its outerend transversely yslotted as'iudicated at 4C,tofacilitate engagement by a suitable screw `and bushing C are put in place, the 'bushing C being aidjustedfto secure the desired Yendwise reaction between the bushingC and end of the pin bin the assembled joint, whilepat the same time holding the headV of the bolt D at a constant vpredetermined position along the axis of the shaft section A in which the bolt head has only sufficient room between the bushing C and the endof the socket in'which it is received to permitV easy rotation of the bolt. The use ofthe interposed ductile washer Vdriver tool for threading it into and out of thek mee/492 member E requires less care in adjusting the part C than would be necessary if the washer E were not used. After the parts are thus threaded together, the pin F is forced home with sufficient pressure to put'the body of the bolt'D under some tension and to increase the reactivezpressure,between the bushing C and the end ofthe pine. With the parts thus connected together it is impossible to loosen the joint by forces tending to screw the pin Z) outof the socket portion A', since the parts are so clamped together that such rotation of the pin Z) in the socket portion A would rotate the 4 bushing C in the direction tending through the bolt D to draw the pin Z) farther into the'socket. vAside from the feature'j ust referred to, the joint'is characterized by the fact that the parts lare -so connected and arranged that the tendency to any initial relative movement of the parts andv conse' quent loosening and weakening of the jointV is practically eliminated. v

The invention is characterized by the following advantages: If the pinnb'is made of chrome-vanadium steel, or other high grade steel alloyfas it may readily be, it is stronger than an integral solid pin portion ofthe shaft B could be, when the latter is made of the best steel which costconsiderations permit to bewused for the purpose.-l The pin portion ofan ordinary threaded pin and socket joint is the weakestgportion of the oint and inconsequence my improved lock joint may be made inherently stronger` than any oint now in use for the same general purpose. In practice,A therefore vthesinvention is particularly` char-` acterized by the ease with which the parts may beY assembled. Since the parts ,that are threaded` together need to be screwed home With suicient force only to insure good metal to metal contact, there is no necessity f-or the Y use of the powerful jacks now commonly employed to couple cable oil well driven shafts,

and lno danger of the thread being stripped orthe pin broken by theforce employe-d in screwing the parts together. parts of the joint may be lubricated with The internal heavy grease to prevent oxidation, and to f'acilitate uncouplingthe shaft sections when this Even though the thi' ads directly connecting the pin to. this shaftsectioirA are stripped, or the pin b or the wall of the socket i portionof the shaft A in which the pin is received is fractured inuse,4the bolt D may servej to hold the shaft sections A and Biltogeth'er WhileV they are Vbeingremovedg thus reducingnthe number of expensive and time Yconsuming fishing operations which have to be conducted. rllhe fact that the bolt D is rotat-able relative to the bushing C makes it possible to edect the exact axial adjustment of the bushing C required for the metal to metal contact between ,thel pin o and bushing C and to secure theproper longitudinal position of the bolt D while at the same time having the opening VD2 in the bolt D in align-jV ment with the passages B3- and Bt, when the parts are tightened up. `Noshims or the like are required vin connection with the taperedl assembled without requiring` new parts and in j many cases without requiring any machin-- ing of the parts. In case the thrust surfaces need be faced off preparatory to reassembly, all that is ordinarily required to insure the desired tightness in the reassembled oint, is the insertion of a suitable washerbetween the abutting ends of the body portions of the shaft sections A- and B. This does not interfere with the maintenance of a constant distance between the axis of the pin ifA and the head of the bolt D. Y Y d i u In some cases I may employ in lieu of the pin member I shown in Figs. l'tol, theA modi-` fied form of pin, ba, fshown in Fig. 5, which'k diifers from the pin Zi primarily in that the pin ba is provided with a circumferential flange (7)3 intermedia-te its threaded portions,V

and against which the ends of the shell portions of the shaft members A and Babut where the joint is assembled, and in that said flange 3 is formed with an axially extending portion b surrounding theA correspondingly reduced end portion of the shaft section B. Viitli this arrangement the portion b4 forms a strong tire or reinforcing band for the wall of the socket B of the shaft section B, materially increasing the resistance of said socket wall to stresses tending to s plit said wall.

Wvhile in accordance with the provisions of the statutes, I haveV illustrated and described the best form of embodiment of my invention now .known Vto me, it will be apparent to those skilled in the art that changes may be niade in the forni" of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that insonie cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is: l

l. In a lock joint construction, a part formed with a socket comprising a tapered and threaded outerV portion and an intermediate oppositely threaded portion, an externally threaded bushingscrewed into said intermediate socket portion,` a bolt having' its head received in the inner portion ofthe socket and. bearing against the inner end of saidbushing and having its body portion extending through said bushing and projecting out of said socket, anda part having a tapered externally threaded portion screwed into said tapered socket portionand formed with an axial passage receiving said bolt, and means connecting said bolt and., v'

second tion. j Y 2.v In a lock Vjoint construction, apart formed with afsocket comprising` a tapered vpart to prevent their Arelative rotaand threaded outer portion and an intermediate oppositely threaded portion, an extcrnallythreaded bushing screwed into said intermediate socket portion, a bolt having itshead received in said socket at the inner side of said intermediate portion, and khavingV its body rportion extending through said bushing and projecting out of said socket,`

and a part having a tapered externally.A threaded pin portionscrewed into said ta-V pered socket portion and formed with anv axiall passage into which "said bolt extends anda tapered key connecting said bolt andv second part to` prevent their relative rotation and to subject them Vto awedging force putting the body `ofthe bolt under tension.4

3. In a look `joint construction, part.,

Yformed with a socket comprising la tapered and threaded outer portion and an intermediate oppositely threaded portion, an externally threaded `bushing screwed intosaid intermediate socket portion, a bolt having its head received in the inner portion of the socket and bearing against the inner end of said bushing and having its body portion extending throughv said bushing` and projecting out of saidsocket, and apart having aV tapered externally'th'readed portion screwed into said tapered socket portion and formed with anaxial passage receiving said bolt, a washer` of kductil'e metal compressed between said bushing and said externally threaded portion, and means connectingsaid bolt `and second kpart to prevent ltheir relative` rotation. i v.

4l. Ina sectional oil well drilling shaft, a shaft section formed with an axial socket at one end comprising a tapered and threaded j outer portion and an intermediate oppositelv threaded portion, anv externally threaded bushing screwed into said intermediatesocket portion, a bolt havingits head received in Y the inner portion ofthe socket and bearing` against the inner end "of said lbushing and having its body portion extendingthrough said bushingand projecting out of said socket, a second shaft section having a threaded lsocket in one end, a part having one end screwed into theV vlast mentioned 'socket and having` its other end tapered andscrewed into saidtapered socket portion, and formed with an axial passage receiving said bolt, andtapered key means connecting said bolt and" --second shaft section to prevent their relative rotation and to subject the end'to a wedging force putting the body of the bolt under` tension.

5.1[n a lock-joint construction, a part 'formed with a-'socket comprising' a tapered and threaded outer portion and an intermediate oppositely ythreaded portion, and fan' axial portion oi. reduced diameter at its inner end, an externally threaded bushing screwed lgviinto said intermediate socket portion, a bolt having its head received in the inner portion of the socket and bearing against the inner end of said bushing and having an axial projection received in, and centered by said p zaxial portion of said socket, and having its.

body portion extending through said bushing t and projecting out of said socket, and a part having a tapered externally threaded portion screwed into said socket portion and formed with an axial passage receiving said bolt, and tapered key means connecting said bolt and Y second part to prevent their relative rotation and to subject them to a wedging ,force putting the body of the bolt under tension.

formed with a socket'comprising a threaded 6. ln alock joint construction, a part New York, andState of New York, this 3rd day of September, A. 111926. f

v LUTHER D. LOVEKIN.

Sii

outer portion and an inner portion, a bolt Y having itshead rotatably received in thein'- ner portion of said'socket and. having its Ybody portion projecting out of said socket,

means carried by said part normally engaging said head to prevent said bolt from being moved axially out oi'said socket, a secondk part having an externally threaded portion screwed into said outer socket portion. andformed with an axial passa-ge receiving said boltkbody portion, and meanszfor maintaining said second part and bolt inV fixed axial relation. f'

7.111 a lock joint construction, apart formed with a socket comprising a threaded outer portion and an inner portion, a bolt having its head rotatably received in theinner portion of said socket and having its body portion projecting out of said socket,'a"sec ond part having anexternally threaded poi'- tion screwed into said outerV socket portion andformed with an axial passage receiving j said bolt body portion, means comprising a lshoulder in said socket portion engaging said bolt head for maintaining the first mentioned part and bolt in ixed axial relation, and

means for preventing axial and relativevrotative movements between said bolt and second part.

8. In a lock joint construction, a part formed with a socket comprising a threaded outer portionand an inner portion, a bolt having its head rotatably received in the iniier portionot said socket and having a pro- 

